JP3223689B2 - Toner for developing electrostatic latent images - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic latent image.
More particularly, the present invention relates to an electrostatic latent image developing toner used in a digital electrophotographic apparatus.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic apparatus, an analog system such as a copying machine which forms an electrostatic latent image on a photosensitive member by irradiating light from a light source to a document and irradiating reflected light thereof to a photosensitive member. Is generally used. Also, as a digital electrophotographic apparatus for developing by supplying a developer containing toner to an electrostatic latent image obtained by digital writing, a printer or an image reader used for output of a computer terminal is used. Digital copying machines, electrophotographic facsimile machines, and the like that form an image based on read image information have been put to practical use.

In a digital electrophotographic apparatus,
An electrostatic latent image is formed in units of dots on the photoreceptor by digital writing such as by irradiating a light beam.
And the obtained toner image is transferred onto a recording medium such as recording paper and fixed to form a recorded image. For this reason, toners used in digital systems are required to have excellent dot reproducibility. In order to satisfy such requirements, it is necessary that the toner has excellent charge stability. That is, it is necessary that the toner has a stable charging performance without a significant change in the toner charge amount due to environmental fluctuations such as humidity and temperature.

Further, the toner is triboelectrically charged by, for example, contact with a carrier in a two-component developing system or by contact with a charging member such as a regulating blade or a sleeve in a developing device in a one-component developing system. However,
If the toner component adheres to the carrier or the charging member during the repetition of the development, the frictional charging ability of the carrier or the charging member with respect to the toner decreases, and as a result, the charge amount of the toner decreases. Therefore, in order to improve the charging stability of the toner, it is necessary that the toner has excellent spent resistance to the carrier and the charging member.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a toner for developing an electrostatic latent image having excellent charging stability. Is what you do. Still another object of the present invention is to provide a toner for developing an electrostatic latent image which is less likely to cause spent on a carrier or a charge applying member.

[0006]

SUMMARY OF THE INVENTION The present invention provides a toner for developing electrostatic latent images which are adjusted by a pulverization method, the toner
However, after the pulverization, the classifying rotor type
The toner particles obtained by classifying fine powder with a classifier.
A toner having an angular shape, and the volume average particle diameter [X] of the toner is 5.0.
１１11.7 μm and a volume average particle size [X] of 5 μm
The relationship with the number% [Y] of particles of m or less is expressed by the following formula: log
Y = −0.16X + k (2.4 ≦ k ≦ 2.65 ) is satisfied (except when the toner is a magnetic toner).
The present invention relates to a toner for developing an electrostatic latent image. The present inventors have conducted intensive studies on toner used in a digital electrophotographic apparatus, and found that the charging stability of the toner is affected by the particle size distribution of the toner and the shape of the toner particles. Was found. Specifically, although the content of the fine powder having a particle size of 5 μm or less and the average particle size of the toner satisfy a certain relationship, and each toner particle is manufactured by a pulverization method, Toner with rounded corners
It has been found that, by using the toner, good charge stability can be ensured and a toner having excellent dot reproducibility can be provided.

In the present invention, the volume average particle size is 5.0
The relationship between the volume average particle diameter [X] and the number% [Y] of toner particles having a volume average particle diameter of 5 μm or less is 11.7 μm.
A toner satisfying Y = −0.16X + k (2.4 ≦ k ≦ 2.65 ) is used. By containing a predetermined amount of toner particles of 5 μm or less corresponding to the average particle diameter of the toner, the charging stability of the toner is improved, and excellent dot reproducibility and clear image reproduction without fogging can be achieved. Become. If the average particle size is larger than 11.7 μm, it is disadvantageous from the viewpoint of high-definition image reproduction. If the average particle size is smaller than 5 μm, manufacturing restrictions (such as cost) increase. The above equation is derived from the graph of FIG. 1 obtained based on experimental data of Examples and Comparative Examples described later. In the figure,
e1 to e10 show Examples 1 to 10 , c1 to c
11 shows Comparative Examples 1 to 11.

Further, in the present invention, a toner having a rounded shape with sharp corners, although adjusted by a pulverizing method, is used. By using a toner having such a shape, it is possible to improve the fluidity of a toner having a small particle diameter, and the uniformity of the charge distribution in one toner particle is improved by removing the corner. (The phenomenon that charges are concentrated on the corners of the toner is eliminated), and the uniformity of the shape of the toner improves the charging stability of the toner.

Usually, in the pulverizing method, a colorant, a binder resin and other desired additives are mixed and kneaded, and the obtained kneaded material is coarsely pulverized, finely pulverized to a desired particle size, and then classified. It is manufactured by The toner particles produced in this way have a fractured surface and have a square irregular shape. For this reason, the shape of each toner particle is different, which is a factor that inhibits fluidity and charging stability.

The above-mentioned sharpened toner is classified (removal of fine powder) by a classification rotor type classifier of the toner adjusted to a desired particle size by pulverization, or mixed by a pulverizer using mechanical impact force. Can be achieved by techniques such as processing,
It is preferable from the viewpoint of cost and the like to perform the classification process and the process for removing corners using a classification rotor type classifier that can simultaneously perform the classification process. By such a treatment, a toner having improved chargeability, printing durability, heat resistance, fluidity and environmental properties can be obtained. This is because, when a classifying rotor type classifier is used, the toner particle surface is smoothed by the action of the impact force of the classifying rotor, and the toner particles which cause fogging and the like by the action of the impact force of the classifying rotor. 1/3 or less of the average particle size or 1 /
Fine particles of 4 or less are strongly adhered and embedded on the toner particle surface to reduce free fine particles, and the dispersion effect by the impact force of the classifying rotor improves the classification efficiency, thereby preventing the fine particles from being mixed into the toner product. For the same reason, generation of a free charge control agent can be prevented. Such an effect cannot be obtained by a conventional air classifier that sifts particles by light weight. When the processing intensity is increased, the toner particles become spherical. However, when the toner particles are completely spherical, the toner passes through when performing blade cleaning, resulting in poor cleaning. It is preferable from the viewpoint of blade cleaning properties to have a rounded shape while maintaining the shape.

As the classifying rotor classifier as described above, various types such as a turbo classifier (manufactured by Nisshin Engineering), Accucut (manufactured by Nippon Donaldson) and the like are known. Among these, the TIPLEX ultrafine powder classifier 50-1000 ATP series (manufactured by Hosokawa Micron Corporation) is preferred. FIGS. 2 and 3 show schematic configuration diagrams of a teeplex multi-wheel classifier in this series. FIG. 2 is a central vertical cross-sectional view, and FIG. 3 is a horizontal cross-sectional view of a classification section.

A raw material (toner particles adjusted to a predetermined particle size by pulverization) is charged from a raw material charging port (12), and is charged as shown in FIG.
Are carried into the classifying chamber via a rotary valve as shown in FIG. The inflow air flows upward from below in the classification chamber, for example, as indicated by arrows. The raw material rises according to the flow, enters the classification section (11) and is classified,
The classified material is taken out from the common fine powder discharge port (13). The classifying section (11) is provided with a plurality of classifying rotors of an individual drive system mounted horizontally. Common speed control is performed through one frequency converter. Further, the toner particles as the raw material may be subjected to air classification before being supplied to the classification rotor type classifier.

The resin used as the binder of the toner of the present invention may be any resin that is generally used as a binder of the toner. (Meth) thermoplastic resins such as acrylic resins, polyolefin resins, polyamide resins, polycarbonate resins, polyether resins, polysulfone resins, polyester resins, epoxy resins, butadiene resins, Alternatively, thermosetting resins such as urea resins, urethane resins, urea resins, epoxy resins, and the like, as well as copolymers, block polymers, graft polymers, and polymer blends thereof can be used. The above resin is not limited to a resin in a complete polymer state such as a thermoplastic resin, but may be a resin containing an oligomer or a prepolymer, a cross-linking agent, or the like as in a thermosetting resin. Is also possible.

In the toner of the present invention, a charge control agent, an anti-offset agent and the like may be further added to the colorant and the binder resin.

For example, as the positive charge control agent, azine compounds Nigrosine base EX, Bontron N-01, 0
2, 04, 05, 07, 09, 10, 13 (manufactured by Orient Chemical Co., Ltd.), oil black (manufactured by Chuo Gosei Kagaku), quaternary ammonium salt P-51, polyamine compound P-52, Sudanchi- Fuschwald BB (Solvent Black 3: CI No. 26150), Fettschwarz HBN (CI No. 26150), Brilliant Spirits Schwarz TN (manufactured by Farben Fabriken Bayer), and further, an alkoxylated amine,
Alkyl amides, molybdate chelate pigments, imidazole compounds and the like can be used.

As the negative charge control agent, for example, chromium complex type azo dyes S-32, 33, 34, 35, 37, 3
8, 40 (manufactured by Orient Chemical Co., Ltd.), Aizen Spiron Black TRH, BHH (manufactured by Hodogaya Chemical Co., Ltd.), Kayaset Black T-22,004 (manufactured by Nippon Kayaku Co., Ltd.), copper phthalocyanine dye S-39 ( Orient Chemical Industry Co., Ltd.), Chromium Complex Salts E-81, 82 (Orient Chemical Industry Co., Ltd.), Zinc Complex Salt E-84 (Orient Chemical Industry Co., Ltd.), Aluminum Complex Salt E-86 (Orient Chemical Industry Co., Ltd.), Calix Allen A system compound E89 (manufactured by Orient Chemical Industries) or the like can be used.

It is desirable to use a charge control agent having a large particle size, which has been subjected to a treatment such as pulverization in advance and adjusted to a desired particle size.

When the charge control agent is dispersed and contained in the toner, the charge control agent is used in an amount of 0.1 to 20 parts by weight, preferably 0.1 to 20 parts by weight, based on 100 parts by weight of the binder resin of the toner.
It is desirable to add 10 parts by weight. When the charge control agent is adhered and fixed to the surface of the toner, the charge control agent is added to the binder resin of the toner in an amount of 0.001 to 100 parts by weight.
It is desirable to add 10 to 10 parts by weight, preferably 0.05 to 2 parts by weight.

Further, an offset preventing agent may be added to the toner according to the present invention, if necessary. Examples of the anti-offset agent include polyolefin waxes such as low molecular weight polyethylene wax, low molecular weight oxidized polyethylene wax, low molecular weight polypropylene wax, low molecular weight oxidized polypropylene wax, higher fatty acid wax, higher fatty acid ester wax, sasol wax, candelilla Wax, carnauba wax and the like can be used alone or in combination of two or more. The offset preventing agent may be added in an amount of 1 to 15 parts by weight, preferably 2 to 8 parts by weight, based on 100 parts by weight of the binder resin of the toner. When using a resin having a polar group such as a polyester resin as the binder resin,
It is desirable to use an oxidized polyolefin-based wax as an anti-offset agent, whereby the compatibility can be improved.

Further, the toner according to the present invention has a surface on which a fluidizing agent is added . The addition of the fluidizing agent is desirably performed by mechanically mixing the toner and the fluidizing agent. As the fluidizer, silica fine particles, titanium dioxide fine particles, alumina fine particles, magnesium fluoride fine particles, silicon carbide fine particles, boron carbide fine particles, titanium carbide fine particles, zirconium carbide fine particles, boron nitride fine particles, titanium nitride fine particles, zirconium nitride fine particles, magnetite Fine particles, molybdenum disulfide fine particles,
Fine particles of aluminum stearate, fine particles of magnesium stearate, fine particles of zinc stearate and the like can be used alone or in combination of two or more. The amount of the fluidizing agent is 0.05 to 2% by weight, preferably 0.1 to 1% by weight, based on the toner. When the amount is less than 0.05% by weight, the fluidity of the toner is insufficient. When the amount is more than 2% by weight, environmental stability is impaired.
When used in a high-humidity environment, a problem of a decrease in toner charge amount occurs. It is preferable to use a fluidizing agent that has been subjected to a hydrophobizing treatment. As the hydrophobizing agent, a silane coupling agent, a titanium coupling agent, a higher fatty acid, a silicone oil, or the like can be used.

[0021]

The toner of the present invention can be used in both a two-component developer used with a carrier and a one-component developer not using a carrier. As a carrier used with the toner of the present invention as a two-component developer,
Any of those conventionally known in the field of electrophotographic developers can be used.

[0023]

EXAMPLES The present invention will be described below with reference to examples, but is not limited thereto.

(Production of Polyester Resin A) A 2-liter four-necked flask was equipped with a reflux condenser, a water separator, a nitrogen gas inlet tube, a thermometer, and a stirrer. , 2) -2,2-
735 g of bis (4-hydroxyphenyl) propane, 292.5 g of polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane, 448.2 g of terephthalic acid, and 22 g of trimellitic acid were charged into a flask. The reaction was carried out while stirring at 220 ° C. while introducing nitrogen into the reactor. The progress of the reaction was monitored while measuring the acid value. When the acid value reached a predetermined value, the reaction was terminated and the softening point was 108.3.
C. Polyester resin A was obtained. The softening point was measured using a Koka type flow tester (CFT-500: manufactured by Shimadzu Corporation).
Using a die with a pore diameter of 1 mm and a pressure of 20 kg / cm
^{2. The} temperature corresponding to 1/2 of the height from the outflow start point to the outflow end point when a 1 cm ² sample was melted and discharged under the condition of a heating rate of 6 ° C / min was defined as the softening point.

(Production of polyester resin B) 735 g of polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2,0) -2,2-bis (4- Hydroxyphenyl)
Polyester resin B having a softening point of 152.5 ° C. was obtained in the same manner as in the production of resin A, except that 292.5 g of propane, 249 g of terephthalic acid, 177 g of succinic acid, and 22 g of trimellitic acid were used.

(Production of Polyester Resin C) A 5-liter four-necked flask was equipped with a reflux condenser, a water separator, a nitrogen gas inlet tube, a thermometer, and a stirrer. , 2) -2,2-
1376 g of bis (4-hydroxyphenyl) propane,
A polyester resin C1 having a softening point of 111 ° C. was obtained in the same manner as in the production of the resin A, except that the reaction was carried out while stirring at 240 ° C. using 472 g of isophthalic acid.

Further, polyoxypropylene (2,2)-
2,2-bis (4-hydroxyphenyl) propane 17
Using 20 g, 860 g of isophthalic acid, 119 g of succinic acid, 129 g of diethylene glycol, and 74.6 g of glycerin, a polyester resin C2 having a softening point of 62 ° C. was obtained in the same manner except that the reaction was carried out while stirring at 240 ° C.

420 parts by weight of the polyester resin C1 and 280 parts by weight of the polyester resin C2 are charged into a Henschel mixer and mixed until sufficiently uniform, and then charged in a heating kneader to obtain 100 parts by weight at a temperature of 120 ° C. Diphenylmethane-4,4 diisocyanate was charged and reacted for 1 hour, and then cooled to obtain a polyester resin C having a urethane bond and a softening point of 140 ° C.

(Example 1) 65 parts by weight of polyester resin A 35 parts by weight of polyester resin B 3 parts by weight of oxidized polypropylene (Biscol TS-200: manufactured by Sanyo Chemical Industries, Ltd.) 5 parts by weight of negative charge control agent Parts (Bontron S-34: manufactured by Orient Chemical Industry Co., Ltd.)-8 parts by weight of carbon black (Mogal L: manufactured by Cabot) The above materials are sufficiently mixed with a Henschel mixer, melt-kneaded with a twin-screw extruder, and then cooled. Thereafter, the mixture was roughly pulverized by a hammer mill and finely pulverized by a jet pulverizer to obtain pulverized toner particles having a volume average particle size of 8.6 μm. Thereafter, a classification rotor type classifier (100/4 ATP: manufactured by Hosokawa Micron)
And the secondary air flow rate is 7,300 rpm.
5Nm ³ / min, total air volume 14.5Nm ³ / mi
Fine powder classification was performed under the conditions of n and Nodge angle scale 8, and toner particles having a particle size distribution shown in Table 1 were obtained.

The toner particles are added to a hydrophobic silica fine powder (H
2000: 0.4% by weight of Nippon Aerosil Co., Ltd.) and conductive titanium oxide (EC300: Titanium Industry Co., Ltd.) 0.2
% By weight and mixed to obtain a toner.

(Examples 2 to 6)
Using ground toner particles having a volume average particle size shown in,
By controlling the classification conditions, a toner having a particle size distribution shown in Table 1 was obtained. Adjustment of the content of the fine powder in the toner can reduce the fine powder content by lowering the rotor rotation speed, increasing the secondary air flow or the total air flow, narrowing the notch angle scale, and the like. Can be increased.

(Comparative Examples 1 to 3)
Using ground toner particles having a volume average particle size shown in,
A toner was produced in the same manner as above except that classification was performed using an air classifier (DS-2, manufactured by NPK) instead of a classification rotor classifier. Table 1 shows the particle size distribution of the obtained toner.

(Comparative Examples 4 to 7)
Using ground toner particles having a volume average particle size shown in,
By controlling the classification conditions, a toner having a particle size distribution shown in Table 1 was obtained.

(Example 7) 100 parts by weight of polyester resin C 2.5 parts by weight of oxidized low molecular weight polypropylene (Biscol TS-200: manufactured by Sanyo Chemical Industry Co., Ltd.) 3 parts by weight of negative charge control agent (Bontron S-34: manufactured by Orient Chemical Industry Co., Ltd. ・ 8 parts by weight of carbon black (Mogal L: manufactured by Cabot) The above materials are sufficiently mixed with a Henschel mixer, melt-kneaded with a twin-screw extruder, cooled, and then cooled. Coarsely pulverized by a hammer mill and finely pulverized by a jet pulverizer to obtain an average particle size of 8.1.
μm of pulverized toner particles were obtained. Then, using a classifying rotor type classifier (100/4 ATP: manufactured by Hosokawa Micron Corporation), the rotor rotation speed is 9500 rpm, and the secondary air flow is 7.5 Nm.
Fine powder classification was performed under the conditions of ³ / min, total air flow of 14.5 Nm ³ / min, and a nodge angle scale of 8, and toner particles having a particle size distribution shown in Table 1 were obtained. To the toner particles, 0.5% by weight of hydrophobic silica fine powder (Cabozil TS500: manufactured by Cabot Corporation) was added and mixed to obtain a toner.

Examples 8 to 10 In Example 7, the toner having the particle size distribution shown in Table 1 was obtained by using the pulverized toner particles having the volume average particle size shown in Table 1 and controlling the classification conditions. Obtained.

Comparative Example 8 In Example 7, pulverized toner particles having a volume average particle size shown in Table 1 were used, and a classifier was replaced with an air classifier (DS) in place of a classifier rotor classifier.
-2: NPK) to obtain a toner having a particle size distribution shown in Table 1.

(Comparative Examples 9 to 11) In Example 7, the toner having the particle size distribution shown in Table 1 was obtained by using the pulverized toner particles having the volume average particle size shown in Table 1 and controlling the classification conditions. Obtained.

[0038]

[Table 1]

(Example of Carrier Production) 100 parts by weight of polyester resin (Mn: 5000, Mw: 115000, Tg: 67 ° C., Tm: 123 ° C.) 500 parts by weight of ferrite fine particles (MFP-2, manufactured by TDK Corporation) Dispersion 3 parts by weight of colloidal silica (Aerosil # 200, manufactured by Nippon Aerosil Co., Ltd.) After sufficiently mixing the above materials with a Henschel mixer, melt-kneading with a twin screw extruder, cooling, coarsely pulverizing, and then finely milling with a jet mill. The carrier was pulverized and further classified using an air classifier to obtain a carrier having an average particle size of 60 μm.

(Evaluation) (Experimental Example 1) The toners of Examples 1 to 6 and Comparative Examples 1 to 7 were mixed with the carrier obtained in the above carrier production example so that the toner mixing ratio was 5% by weight. Component developers were prepared.

The following items were evaluated for the obtained developer.

(Evaluation of Environment Fluctuation Width) First, the above developer was stirred for 10 minutes by a roll mill under an N / N environment (23 ° C., 38%). This developer is used in an L / L environment (10
(15 ° C. 15%) and in an H / H environment (30 ° C. 85%) for 2 hours or more, and then the charge amount under the environment was measured.
If the difference between the charge amount of the developer left under the L / L environment and the charge amount of the developer left under the H / H environment is 12 μC / g or less, an image stable against environmental fluctuations can be obtained. be able to. On the other hand, if it is larger than 12 μC / g, it is difficult to perform control (stabilization of image quality) on the device side, which is not preferable. Table 2 shows the results.

(Retention of Charge Amount after 10,000 Printings (10K) After Printing) The obtained developer was applied to an electrophotographic printer (SP-
(500: manufactured by Minolta Camera Co., Ltd.), and the developer after 10K printing was taken out to separate only the carrier. The charge amount Q ′ when the separated carrier and the toner were remixed was measured, and the charge amount holding ratio [(Q ′ /
Q) × 100: Q is the initial charge amount]. Table 2 shows the results.

(Evaluation of Fogging) The images at the initial stage and after 10K printing were visually observed and judged. 5: very good without fog, 4: almost no fogging, 3: fogging but no practical problem, 2: much fogging and practically problematic, 2; The most common was evaluated as 1. Table 2 shows the results.

(Evaluation of Cleaning Ability) The surface of the photoreceptor after passing through the cleaning blade after 10K printing was visually observed.
Those having poor cleaning due to slippage of the toner particles were evaluated as x. Table 2 shows the results.

[0046]

[Table 2]

(Experimental Example 2) Using the toners of Examples 7 to 10 and Comparative Examples 8 to 1 as a one-component developer, image formation was performed using an electrophotographic printer (SP101: manufactured by Minolta Camera Co., Ltd.). The following items were evaluated.

(Difference in image density after initial printing and after printing 1000 sheets (1K)) The optical reflection density of the image after initial and 1K printing was measured with a Macbeth reflection densitometer in an N / N environment.
The difference ΔID was obtained. If ΔID is less than 0.2, the difference in image density between the initial stage and after printing is small, indicating that the charge amount is stable. If ΔID is larger than 0.2, it is considered that the toner is fused to the regulating blade or sleeve of the developing device, and the charge amount is changed. Table 3 shows the results. In Examples 7 to 10 , the differences ΔID between the ID after 1K printing under the L / L environment and the ID after 1K printing under the H / H environment were all less than 0.2. On the other hand, for Comparative Examples 8 to 11, ΔID is N
/ N environment, toner fusion to a sleeve or the like occurs under the L / L environment, so that uniform charging cannot be obtained. The passage property became poor, and the follow-up property of the solid black was deteriorated. Further, in an H / H environment, the charge amount was reduced, and a toner amount exceeding an appropriate amount was developed, so that the toner consumption increased.

[0049]

[Table 3]

[0050]

An object of the present invention is to provide a toner for developing an electrostatic latent image having excellent charging stability.

It is a further object of the present invention to provide a toner for developing an electrostatic latent image, which causes less spent on a carrier or a charging member.

[Brief description of the drawings]

FIG. 1 shows a graph in which the number% Y of particles having a particle size of 5 μm or less is plotted against the volume average particle diameter X of the toner.

FIG. 2 is an example of a classifying rotor type classifier, showing a central vertical sectional view thereof.

FIG. 3 is a horizontal sectional view of a classification section of the classification rotor type classifier of FIG. 2;

[Explanation of symbols]

11: Classification section, 12: Raw material input port, 13: Common fine powder discharge port

────────────────────────────────────────────────── ─── Continuation of the front page Examiner Mina Asano (56) References JP-A-1-112253 (JP, A) JP-A 1-219757 (JP, A) JP-A 4-145449 (JP, A) JP-A-5-15803 (JP, A) JP-A-5-212308 (JP, A) JP-A-6-317931 (JP, A) JP-A-6-75428 (JP, A) JP-A-6-59507 ( JP, A) JP-A-7-88393 (JP, A) JP-A-61-61627 (JP, A) JP-A-63-249155 (JP, A) JP-A-2-93545 (JP, A) JP JP 1-149059 (JP, A) JP 1-2221759 (JP, A) JP 4-212174 (JP, A) JP 2-103560 (JP, A) (58) Fields studied (Int .Cl. ⁷ , DB name) G03G 9/08-9/087

Claims (1)

(57) [Claims] In a toner for developing an electrostatic latent image adjusted by a pulverization method, the toner is added with a fluidizing agent after the pulverization.
Classification of fine powder removal with a classification rotor type classifier without adding
To obtain toner particles by adding a fluidizing agent to the obtained toner particles.
Is, and the toner particles have a balanced shape of the corners, the volume average particle diameter of the toner [X] is 5.0～11.7Myuemu, and the volume average particle diameter [X] and 5μm or less of particles Is expressed by the following formula: logY = −0.16X +
k (2.4 ≦ k ≦ 2.65 ) (however,
And does not include magnetic toner. A) a toner for developing an electrostatic latent image.